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| United States Patent |
5,594,087
|
|
K onig
, et al.
|
January 14, 1997
|
Polyurethane thickeners and their use for thickening aqueous systems
Abstract
Water soluble or water dispersible polyurethane, which are suitable as
thickeners for aqueous systems and prepared from a selected alcohol
component a) based on a hydrophilic/hydrophobic mixture of alcohols and an
isocyanate component b), and to their use for thickening aqueous systems.
| Inventors:
|
K onig; Klaus (Odenthal, DE);
Mazanek; Jan (K oln, DE);
Schwindt; J urgen (Leverkusen, DE);
Dietrich; Manfred (Leverkusen, DE);
Klein; Gerhard (Monheim, DE)
|
| Assignee:
|
Bayer Aktiengesellschaft (Leverkusen, DE)
|
| Appl. No.:
|
286040 |
| Filed:
|
August 4, 1994 |
Foreign Application Priority Data
| Aug 16, 1993[DE] | 43 27 481.1 |
| Current U.S. Class: |
528/44; 524/589; 524/590; 528/76; 528/85 |
| Intern'l Class: |
C08G 018/00 |
| Field of Search: |
528/44,76,85
524/589,590
|
References Cited
U.S. Patent Documents
| 3362780 | Jan., 1968 | Kuth et al. | 8/42.
|
| 4079028 | Mar., 1978 | Emmons et al. | 260/29.
|
| 4092275 | May., 1978 | Reisch et al. | 521/137.
|
| 4155892 | May., 1979 | Emmons et al. | 260/29.
|
| 4499233 | Feb., 1985 | Tetenbaum et al. | 524/591.
|
| 5023309 | Jun., 1991 | Kruse et al. | 528/49.
|
| Foreign Patent Documents |
| 0031777 | Jul., 1981 | EP.
| |
| 096882 | Dec., 1983 | EP.
| |
| 103147 | Mar., 1984 | EP.
| |
| 0495373 | Jul., 1992 | EP.
| |
| 498442 | Aug., 1992 | EP.
| |
| 3630319 | Mar., 1988 | DE.
| |
Primary Examiner: Seidleck; James J.
Assistant Examiner: Truong; Duc
Attorney, Agent or Firm: Gil; Joseph C., Roy; Thomas W.
Claims
What is claimed is:
1. A water soluble or water dispersible polyurethane, which is suitable as
a thickener for aqueous systems, and is prepared by reacting at an NCO/OH
equivalent ratio of 0.8:1 to 1.4:1
a) an alcohol component containing
a1) 25 to 80 mol-% of one or more compounds corresponding to the formula
R.sub.2 --O--A.sub.y H
a2) 10 to 60 mol-% of one or more compounds corresponding to the formula
HO--A.sub.z --(BO).sub.z' --A.sub.z" --H
and
a3) 5 to 60 mol-% of one or more compounds corresponding to the formula
HO--R.sub.3 --OH
with
b) an isocyanate component having an average NCO-functionality of 1.5 to
2.5 and containing at least one organic isocyanate corresponding to the
formula
R.sub.1 (NCO).sub.x
wherein
R.sub.1 represents an aliphatic, cycloaliphatic, aromatic or araliphatic
hydrocarbon radical having 6 to 28 carbon atoms and optionally inert
substituents,
R.sub.2 represents an aliphatic hydrocarbon radical having 12 to 24 carbon
atoms,
R.sub.3 represents an aliphatic or araliphatic hydrocarbon radical having 4
to 36 carbon atoms and optionally ether oxygen atoms, provided that at
least 3 carbon atoms are arranged between the two hydroxyl groups and the
numerical ratio of carbon atoms to the ether oxygen atoms optionally
present is at least 2.5:1,
A) represents an alkylene oxide radical having 2 or 3 carbon atoms, wherein
the proportion of radicals having 3 carbon atoms is not greater than 40
mol-%, and different alkylene oxide radicals may be present in any
distribution,
B) represents an aliphatic hydrocarbon radical having 2 to 18 carbon atoms,
a cycloaliphatic hydrocarbon radical having 4 to 13 carbon atoms or an
aromatic hydrocarbon radical having 6 to 15 carbon atoms,
x represents an integer or on average a fractional number from 1.5 to 2.5,
y represents a number of 5 to 200,
z and z" each represent numbers from 0 to 400, provided that the sum of
z+z" is 10 to 400, and
z' represents 0 or 1,
wherein the sum of the percentages of a1), a2) and a3) total 100 and the
weight of the radicals R.sub.2 and R.sub.3, based on the total weight of
the component a), is less than 15% by weight.
2. The polyurethane of claim 1 wherein said NCO/OH equivalent ratio is
0.9:1 to 1.2:1.
3. The polyurethane of claim 1 wherein R.sub.2 represents an aliphatic
hydrocarbon radical having 16 to 18 carbon atoms.
4. The polyurethane of claim 2 wherein R.sub.2 represents an aliphatic
hydrocarbon radical having 16 to 18 carbon atoms.
5. The polyurethane of claim 1 wherein A consists essentially of ethylene
oxide radicals, y represents a number of 30 to 150, z and z" each
represent numbers of 0 to 300, provided that the sum of z+z" is 100 to 300
and z' represents 0.
6. The polyurethane of claim 2 wherein A consists essentially of ethylene
oxide radicals, y represents a number of 30 to 150, z and z" each
represent numbers of 0 to 300, provided that the sum of z+z" is 100 to
3900 and z' represents 0.
7. The polyurethane of claim 3 wherein A consists essentially of ethylene
oxide radicals, y represents a number of 30 to 150, z and z" each
represent numbers of 0 to 300, provided that the sum of z+z" is 100 to 300
and z' represents 0.
8. The polyurethane of claim 4 wherein A consists essentially of ethylene
oxide radicals, y represents a number of 30 to 150, z and z" each
represent numbers of 0 to 300, provided that the sum of z+z" is 100 to 300
and z' represents 0.
9. The polyurethane of claim 1 wherein component a3) consists essentially
of .omega.,.omega.'-dihydroxyalkanes having 6 to 18 carbon atoms.
10. The polyurethane of claim 2 wherein component a3) consists essentially
of .omega., .omega.'-dihydroxyalkanes having 6 to 18 carbon atoms.
11. The polyurethane of claim 3 wherein component a3) consists essentially
of .omega., .omega.'-dihydroxyalkanes having 6 to 18 carbon atoms.
12. The polyurethane of claim 4 wherein component a3) consists essentially
of .omega., .omega.'-dihydroxyalkanes having 6 to 18 carbon atoms.
13. The polyurethane of claim 5 wherein component a3) consists essentially
of .omega., .omega.'-dihydroxyalkanes having 6 to 18 carbon atoms.
14. The polyurethane of claim 6 wherein component a3) consists essentially
of .omega., .omega.'-dihydroxyalkanes having 6 to 18 carbon atoms.
15. The polyurethane of claim 7 wherein component a3) consists essentially
of .omega., .omega.'-dihydroxyalkanes having 6 to 18 carbon atoms.
16. The polyurethane of claim 8 wherein component a3) consists essentially
of .omega., .omega.'-dihydroxyalkanes having 6 to 18 carbon atoms.
17. A composition comprising an aqueous polymer dispersion and the water
soluble or water dispersible polyurethane of claim 1.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to new hydrophilic/hydrophobic polyurethanes which
are soluble or dispersible in water, suitable as thickeners for aqueous
systems and distinguished by having a particularly efficient thickening
action, and to their use for the thickening of aqueous systems.
2. Description of the Prior Art
Polyurethane-based thickeners for aqueous systems are described in numerous
publications (cf., for example, DE-OS 1,444,243, DE-OS 3,630,319, EP-A
0,031,777, EP-A 0,307,775, EP-A 0,495,373, U.S. Pat. No. 4,079,028, U.S.
Pat. No. 4,155,892, U.S. Pat. No. 4,499,233 and U.S. Pat. No. 5,023,309).
These prior art thickeners have in common the simultaneous presence of (i)
hydrophilic segments in a quantity of at least 50% by weight, (ii)
hydrophobic segments in a quantity of at most 10% by weight and (iii)
urethane groups. "Hydrophilic segments" are understood in this connection
to be polyether chains having at least 5 alkylene oxide units, in which
the alkylene oxide units contain at least 60 mol-% of ethylene oxide
units. "Hydrophobic segments" are understood in this connection to be in
particular hydrocarbon segments having at least 6 carbon atoms
incorporated inside the chain and/or preferably terminally.
The thickeners according to the invention described below also preferably
correspond to this definition.
These polyurethane thickeners are suitable as auxiliary substances for
adjusting the flow properties of aqueous systems such as automotive and
industrial coatings, finishes and paints, printing inks and textile dyes,
pigment printing pastes, pharmaceutical and cosmetic compositions,
formulations for plant protection and filler dispersions.
Although the known polyurethane thickeners are widely used, they have a
thickening action that is too low for many fields of application. As a
result they must either be used in comparatively high concentrations or
else other measures must be taken to increase the viscosity, such as
increasing the concentration of the pigment or solids. However, this may
lead to undesirable changes in the properties associated with the
application of the paints or other formulations prepared, for example,
flow, curing behavior, gloss or hiding power.
A particular problem in the use of polyurethane thickeners is that they
must have an effective action not only at low shear rates (which is
important for the settling behavior and flow of paints), but also at high
rates of shear (high shear range) which occur when formulations are
applied, for example, with a brush or a roller or by spraying. For this
reason in the prior art as a rule, two basic types of thickeners are used
in one formulation for the respective ranges of shear rates, or otherwise
auxiliary substances are added, such as solvents, in order to reduce the
low-shear viscosity.
In the past many attempts were made to improve the effectiveness of aqueous
polyurethane thickeners. Thus, for instance, the thickening action at low
shear rates (low shear range) could be improved by increasing the length
or the proportion of hydrophobic end groups. However, the effectiveness of
such thickeners in the high shear range is inadequate for many fields of
application.
On the other hand, improvements were attained in the high shear range, for
example, by the incorporation of substituted ethane diols or ethylene
diamines having long hydrophobic side chains. However, such thickeners
showed inadequate effectiveness in the low shear range.
These thickeners therefore have the feature in common that they contain as
hydrophobic groups either terminal alkyl groups and/or branched groups
incorporated in the polymer chains by the reaction of hydrophobic
short-chain diols or diamines containing lateral groups with, for example,
diisocyanate prepolymers.
An object of the present invention is to provide new thickeners based on
polyurethanes for aqueous or predominantly aqueous systems which have a
well-balanced thickening action both in the low shear range and in the
high shear range.
This object may be achieved with the water soluble or water dispersible,
hydrophilic/hydrophobic polyurethanes according to the invention described
in more detail below. Essential to the invention is the incorporation of
selected hydrophilic or hydrophobic segments using a specific mixture of
alcohols as co-reactant for the isocyanate component.
SUMMARY OF THE INVENTION
The present invention relates to water soluble or water dispersible
polyurethanes, which are suitable as thickeners for aqueous systems, and
are prepared by reacting at an NCO/OH equivalent ratio of 0.8:1 to 1.4:1
a) an alcohol component containing
a1) 25 to 80 mol-% of compounds corresponding to the formula
R.sub.2 --O--A.sub.y H
a2) 10 to 60 mol-% of compounds corresponding to the formula
HO--A.sub.z --(BO).sub.z' --A.sub.z" --H
and
a3) 5 to 60 mol-% of compounds corresponding to the formula
HO--R.sub.3 --OH
with
b) an isocyanate component having an average NCO-functionality of 1.5 to
2.5 and containing at least one organic isocyanate corresponding to the
formula
R.sub.1 (NCO).sub.x
wherein
R.sub.1 represents an aliphatic, cycloaliphatic, aromatic or araliphatic
hydrocarbon radical having 6 to 28 carbon atoms and optionally inert
substituents,
R.sub.2 represents an aliphatic hydrocarbon radical having 12 to 24 carbon
atoms,
R.sub.3 represents an aliphatic or araliphatic hydrocarbon radical having 4
to 36 carbon atoms and optionally ether oxygen atoms, provided that at
least 3 carbon atoms are arranged between the two hydroxyl groups and the
numerical ratio of carbon atoms to the ether oxygen atoms optionally
present is at least 2.5:1,
A) represents an alkylene oxide radical having 2 or 3 carbon atoms, (i.e.
ethylene oxide or propylene oxide radicals), wherein the proportion of
radicals having 3 carbon atoms is not greater than 40 mol-%, and different
alkylene oxide radicals may be present in any distribution,
B) represents an aliphatic hydrocarbon radical having 2 to 18 carbon atoms,
a cycloaliphatic hydrocarbon radical having 4 to 13 carbon atoms or an
aromatic hydrocarbon radical having 6 to 15 carbon atoms,
x represents an integer or on average a fractional number from 1.5 to 2.5,
y represents a number of 5 to 200,
z and z" each represent numbers from 0 to 400, provided that the sum of
z+z" is 10 to 400, and
Z' represents 0 or 1,
wherein the sum of the percentages of a1), a2) and a3) total 100 and the
weight of the radicals R.sub.2 and R.sub.3, based on the total weight of
the component a), is less than 15% by weight.
The invention also relates to the use of these polyurethanes for the
thickening of aqueous systems.
DETAILED DESCRIPTION OF THE INVENTION
The alcohol component a 1) is selected from hydrophobic/hydrophilic
monovalent alcohols corresponding to the formula
R.sub.2 --O--A.sub.y H
wherein
R.sub.2, A and y have the meanings given above.
Preferably,
R.sub.2 represents an aliphatic hydrocarbon radical having 16 to 22, more
preferably 16 to 18 carbon atoms,
A represents ethylene oxide and/or propylene oxide, provided that at least
60 mol-%, more preferably 100 mol-%, of the radicals are ethylene oxide
radicals, and
y represents a number from 30 to 150.
The preparation of polyether alcohols a1) takes place in known manner by
the alkoxylation of the corresponding monovalent alcohols corresponding to
the formula
R.sub.2 --OH
using ethylene oxide and optionally propylene oxide in admixture and/or in
any sequence. Suitable starting materials include the isomeric dodecanols,
tetradecanols, hexadecanols, octadecanols, behenyl alcohol, alcohols
formed by the hydrogenation of fatty acid mixtures and mixtures of such
monovalent alcohols. The linear primary alcohols are particularly
preferred as starting materials for the preparation of alcohol component
a1).
Alcohol component a2) is selected from hydrophilic diols corresponding to
the formula
HO--A.sub.z --(BO).sub.z' --A.sub.z" --H
wherein
A has the meaning and preferred meaning given above,
B has the meaning given above and preferably represents an aliphatic
hydrocarbon radical having 2 to 6 carbon atoms, a cycloaliphatic
hydrocarbon radical having 6 carbon atoms or an aromatic hydrocarbon
radical having 6 to 13 carbon atoms,
z and z" have the meanings given above and each preferably represent
numbers from 0 to 300, provided that the sum of z and z" is 100 to 300,
and
z' represents 0 or 1, preferably 0.
The preparation of diols a2) takes place by the known alkoxylation of
suitable starter molecules using ethylene oxide and optionally propylene
oxide as described above. Suitable starter molecules include water,
ethylene glycol, oligoethylene glycol, propylene glycol, oligopropylene
glycol, the isomeric butanediols or hexanediols, neopentyl glycol,
hydroquinone, resorcinol, 1,4-dihydroxyhexane,
4,4'-dihydroxydiphenylmethane and 1,4-bis-(hydroxymethyl)-cyclohexane. The
use of water or ethylene glycol as starting materials and ethylene oxide
as the only alkylene oxide is particularly preferred, such that the
component a2) is based on polyethylene glycols.
The alcohol component a3) is selected from diols corresponding to the
formula
HO--R.sub.3 --OH
wherein R.sub.3 has the meaning given above. In these diols R.sub.3
preferably represents a linear or branched, more preferably linear
aliphatic hydrocarbon radical having 4 to 36, in particular 6 to 18
hydrocarbon atoms. The diols may also contain ether oxygen atoms, provided
that the numerical ratio of carbon atoms to ether oxygen atoms is at least
2.5:1, preferably at least 3:1.
Specific examples of suitable diols a3) are butanediol-1,4, neopentyl
glycol, hexanediol-1,6, di-, tri- and tetrapropylene glycol,
octanediol-1,8,2-ethylhexanediol-1,3,2,2,4-trimethylpentanediol-1,3,2,4,4-
trimethylhexane-diol-1,6, decanediol-1,10, nonanediol-1,9,
dodecanediol-1,12, hexadecanediol-1,16, octadecanediol-1,12, the diol
based on hydrogenareal dimeric fatty acid that is available as Pripol 2023
by Henkel, hydrogenated aromatic diols and bis-2-hydroxyalkyl ether
aromatic diols. Low molecular weight oligoethylene glycols such as di-,
tri- or tetraethylene glycol may also be used but are less preferred.
Mixtures of different diols may also be used as component a3).
Alcohol component a) preferably contains 30 to 70, in particular 35 to 65
mol-% of alcohols a1); 15 to 45, in particular 20 to 40 mol-% of alcohols
a2); and 15 to 45, in particular 15 to 40 mol-% of alcohols a3), wherein
the percentages total 100. Components a1) and a2) are preferably selected
such that the sum of the average molecular weights of components a 1) and
a2), which can be calculated from the hydroxyl group content and the
hydroxyl functionality, is between 6,000 and 18,000. This sum may be
achieved by using comparatively short chain polyethers a1) in combination
with long chain polyethers a2) or vice versa.
Isocyanate component b) is selected from compounds corresponding to the
formula
R.sub.1 (NCO).sub.x
wherein R.sub.1 and x have the meanings given above.
Preferred isocyanates are those wherein
R.sub.1 represents an aliphatic, cycloaliphatic, aromatic or araliphatic
hydrocarbon radical having 6-21, in particular 6-10 carbon atoms and
x represents an integer or on average a fractional number from 1.8 to 2.2,
more preferably 1.9 to 2.1 and most preferably 2.
Both single compounds corresponding to the given definition and mixtures of
isocyanates may thus be used as component b). Examples include
hexamethylene diisocyanate, dodecamethylene diisocyanate, isophorone
diisocyanate, 4,4'-diisocyanatodicyclohexylmethane,
1,4-diisocyanatocyclohexane, 2,4- and 2,6-diisocyanatotoluene and
4,4'-diisocyanatodiphenylmethane and mixtures thereof with the 2,4'-isomer
and optionally the 2,2'-isomer and/or mixtures thereof with its higher
polyisocyanates. Also suitable are the known higher functional coating
polyisocyanates such as polyisocyanates prepared from hexamethylene
diisocyanate and having biuret groups or isocyanurate groups.
Monoisocyanates, such as hexyl isocyanate, phenyl isocyanate or stearyl
isocyanate, may also be used as a portion of component b).
Component b) is used in the preparation of the polyurethanes according to
the invention in quantities which correspond to an NCO/OH equivalent
ratio, based on the isocyanate groups of component b) and the hydroxyl
groups of component a), of 0.8:1 to 1.4:1, preferably 0.9:1 to 1.2:1. It
is preferable to operate with equivalent amounts of components a) and b),
but due to the often unavoidable water content of the hydrophilic
polyether components, a small excess of isocyanate within the limits of
the preceding ranges is frequently advantageous to compensate for the
moisture.
The preparation of the polyurethanes according to the invention generally
takes place at a temperature of 60.degree. to 150.degree. C., preferably
80.degree. to 120.degree. C. Conventional catalysts such as dibutyltin
dilaurate or tin(II) octoate can be used to accelerate the reaction.
Generally the final viscosity of the polyurethanes according to the
invention at the reaction temperature is low enough to be dispense with
inert solvents. However, when solvents have been used (such as toluene or
xylene), particularly in the dehydration of alcohols a) by azeotropic
distillation, they may remain in the reaction mixture and be removed only
after the reaction is over.
The preparation of the polyurethanes according to the invention takes place
in a one-step or multi-step reaction. The reaction of the entire quantity
of component a) with the entire quantity of component b) is understood as
being a one-step reaction. In a multi-step reaction a portion of alcohol
component a), or, for example, only one of the single components a1), a2)
or a3) is reacted with the entire quantity of the isocyanate component b)
and subsequently the resulting NCO-prepolymer is reacted with the
remaining quantity of alcohols a). The order of the reactions in this case
is essentially immaterial.
The polyurethanes according to the invention essentially colorless to
yellowish waxes having softening points or softening regions within the
temperature range of 40.degree. to 80.degree. C. For subsequent use it is
often advantageous to mix the polyurethanes according to the invention
with additives, such as formulating agents, solvents, water, emulsifiers
or stabilizers, to make liquid formulations.
The polyurethanes according to the invention are suitable as thickeners for
aqueous or predominantly aqueous systems such as paints, printing pastes
and pigment pastes, filler dispersions and pigment dispersions, auxiliary
substances for textiles, leather and paper, preparations for petroleum
production, preparations for detergents, adhesives, waxes for polishes,
formulations for pharmaceutical and veterinary purposes, formulations for
plant protection and cosmetic articles. Water alone can also be thickened
with the polyurethane thickeners according to the invention. The thickened
water may then optionally be mixed with further additives or added to
aqueous preparations. The thickeners according to the invention may also
be used in mixtures with other thickeners such as those based on
polyacrylates, cellulose derivatives or inorganic thickeners.
Examples of aqueous systems that can be thickened according to the
invention are aqueous polymer dispersions such as polyacrylate
dispersions, aqueous dispersions of mixtures of polymerizates of
olefinically unsaturated monomers, aqueous polyvinyl acetate dispersions,
aqueous polyurethane dispersions, aqueous polyester dispersions and
particularly ready-for-use preparations of the kind discussed above based
on such dispersions.
The thickeners according to the invention may be used as solids, preferably
as granules or optionally as powders. However, It is preferred to use
liquid formulations, which besides the polyurethanes according to the
invention contain water, solvents (such as butyl diglycol, isopropanol,
methoxypropyl acetate, ethylene glycol and/or propylene glycol), nonionic
emulsifiers, tensides and/or optionally other additives. These additives
considerably facilitate the incorporation of the thickeners according to
the invention into aqueous or predominantly aqueous systems.
Ready-to-use preparations of the thickeners according to the invention are
aqueous solutions or dispersions having a solids content of 10 to 80,
preferably 30 to 60, and more preferably 40 to 50% by weight.
The quantity of thickener which is added to the aqueous or predominantly
aqueous systems in order to attain the desired thickening depends in each
case on the intended use and can be determined by a few preliminary tests
by the person skilled in the art. Generally, from 0.05 to 10% by weight,
preferably 0.1 to 4% by weight and more preferably 0.1 to 1% by weight of
the thickener according to the invention is used, based on the weight of
the aqueous system to be thickened. These percentages refer to the solids
content of the thickener and the aqueous system to be thickened.
The effectiveness of the thickeners according to the invention can be
evaluated by known methods, for example, in a Haake rotating viscometer, a
Stormer viscometer, a Brookfield viscometer or an ICI viscometer.
The following examples further illustrate the invention. All molecular
weight values refer to the average molecular weight of the alcohols, which
can be calculated from the OH-content and the OH-functionality.
EXAMPLES
Example 1
748 g (0.2 mol) of a polyethylene oxide polyether based on stearyl alcohol
and having an average molecular weight of 3740 (=a1), together with 748 g
(0.1 mol) of polyethylene glycol having a molecular weight of 7480 (=a2),
were melted, heated to 120.degree. C. and dehydrated for 3 hrs at 10 mbar.
Following the addition of 5.9 g (0.05 mol) of hexanediol-1,6 (=a3), 46.2 g
(0.275 mol) of hexamethylene diisocyanate (HDI=b) was added all at once
with stirring at 80.degree. C. After 2 h at 80.degree. C., 200 mg of tin
dioctate was added as a catalyst and the reaction completed in 2 hours at
120.degree. C. After pouring onto a metal sheet and cooling, a pale
yellowish wax was obtained.
Examples 2 to 8
The procedure described in Example 1 was followed, maintaining the
components a 1 ) and a2) but varying the type and/or quantity of the
components a3) and b). Details are set forth in Table 1 below.
TABLE 1
__________________________________________________________________________
Component a3)
Example No.
Structure
Mol Diisocyanate (b)
NCO/OH-ratio
Catalyst
__________________________________________________________________________
2 Hexanediol-1,6
0.1 HDI 1.05 Dibutyltin dilaurate
(200 mg)
3 Hexanediol-1,6
0.1 2,4-tolylene
1.1 Diazabicyclo-
diisocyanate octane
(100 mg)
4 Dodecane-
0.035
HDI 1.0 --
diol-1,12
5 Dodecene-
0.05
HDI 1.1 Titanium
diol-1,12 tetrabutylate
(200 mg)
6 Dodecane-
0.1 HDI 1.1 Dibutyltin
diol-1,12 dilaurate
(200 mg)
7 Dodecane-
0.05
Isometric Mixture of
0.95 Dibutyl dilaurate
diol-1,12 2,4- and 2,6-tolylene
(200 mg)
diisocyanate 80:20
8 Octadecane-
0.025
HDI 1.1 Dibutyltin dilaurate
diol-1,18 (200 mg)
__________________________________________________________________________
Example 9
196 g (0.2 mol) of a polyethylene oxide polyether (=a1) based on
dodecanol-1 and having an average molecular weight of 980, after
dehydration, was reacted while stirring for 12 h at 100.degree. C. with
106.4 g of 4,4'-diisocyanatodicyclohexylmethane (available as Desmodur W
from Miles) (=b). Then 1,360 g (0.2 mol) of dehydrated polyethylene glycol
having a molecular weight of 6 800 (=a2) and 19.4 g (0.1 mol) of
tetraethylene glycol (=a3) was stirred in. After 1 h 500 mg of tin
dioctoate was added and the reaction was completed in 5 h at 120.degree.
C. Upon cooling an almost colorless wax was obtained.
Example 10
600 g (0.2 mol) of polyethylene glycol having a molecular weight of 3000
(=a2) was dehydrated, mixed at 100.degree. C. with 122.1 g (0.55 mol) of
isophorone diisocyanate (=b) and reacted with stirring over a period of 8
h (titrimetric NCO-control). Then the prepolymer was mixed with 1200 g
(0.3 mol) of a polyethylene oxide polyether based on a commercial mixture
of fatty alcohols (C.sub.14 to C.sub.20, average chain length 17.5) and
having an average molecular weight of 4000 (=a 1) and subsequently with
20.8 g (0.2 mol) of neopentyl glycol (=a3). After 1 h at 120.degree. C,
500 mg of dibutyltin dilaurate was added and the reaction completed after
3 h at 120.degree. C. (NCO-control by SR measurements). A light yellow wax
was formed.
Example 11
740 g (0.2 mol) of a polyethylene oxide polyether based on behenyl alcohol
and having an average molecular weight of 3700 (=a1) and 680 g (0.1 mol)
of a polyethylene glycol having an average molecular weight of 6800 (=a2)
and 1 l of toluene were azeotropically dehydrated together at 120.degree.
C./1 mbar. After cooling to 60.degree. C., 75 g (0.3 mol) of
4,4'-diphenylmethane diisocyanate (=b) in liquid form was stirred in and
reacted over a period of 12 h to form a prepolymer. Then 9 g (0.1 mol) of
butanediol-1,4 (=a3) was added and the temperature elevated to 100.degree.
C. After 4 h of stirring at 100.degree. C., no more NCO could be detected
by SR spectroscopy. On cooling a yellow wax was obtained.
Examples of Application
The following Examples A1 to A11 demonstrate that with the use of the
thickeners according to the invention latex paints can be obtained which
display improved working properties (for example, sedimentation stability
of the paint and its applicability, flow and suitability for forming
greater film thicknesses). Films produced by brush application of the
latex paint to a plastic foil (Linetta foil) were evaluated on a scale of
1 (very good) to 5 (very bad). The viscosities of the paints produced with
the thickeners according to the invention and the yield values were
measured with a Haake viscometer or ICI viscometer at 1 to 80 or at
10.sup.4 s.sup.-1.
Examples A 1 to A 11
Acrylate-based latex gloss paints containing 5 g each of the polyurethane
thickeners according to the invention and the following ingredients were
prepared:
______________________________________
AMP 90.sup.1) 2.5 g
Borchigen ND.sup.2), 25% in water
13.6 g
Borchigen DFN.sup.2), 100%
5.0 g
Neocryl AP 2860.sup.3)
3.2 g
TiO.sub.2 -RHD-2 225.0 g
Methoxybutanol 17.0 g
Propylene glycol 17.0 g
Butyl diglycol 17.0 g
Water 44.7 g
Neocryl XK 62.sup.4) 540.0 g
Water 110.0 g
______________________________________
.sup.1) (2-Amino-2-methylpropanol-1, 90% in water), Angus Chemie GmbH,
Essen
.sup.2) Wetting agent, Gebr. Borchers AG, Goslar
.sup.3) Defoaming agent, ICI Resins, Runcorn, England
.sup.4) Anionic copolymer emulsion based on acrylate/styrene, ICI Resins
The results of the tests are set forth in Table 2.
TABLE 2
______________________________________
Viscosity at
Thickener [s.sup.-1 ]
Example Example [Pa .multidot. s]
Working
No. No. 1 10 10.sup.4
properties
______________________________________
A1 1 28.3 22.1 0.17 2
A2 2 22.7 20.2 0.16 2
A3 3 22.0 17.8 0.14 1-2
A4 4 28.1 18.1 0.16 2-3
A5 5 26.5 17.2 0.15 1
A6 6 23.3 19.3 0.15 1
A7 7 34.2 27.7 0.16 3
A8 8 29.3 21.2 0.15 1
A9 9 27.3 19.6 0.14 2
A10 10 21.6 27.4 0.16 1
A11 11 29.2 21.8 0.15 1-2
Comparison 17.3 16.1 0.07 5.sup.b)
Example 1.sup.a)
______________________________________
.sup.a) Comparison Example 1 corresponded to Example A1, but as thickener
a polyurethane was used which had been prepared analogously to Example 1,
but without component a3) and a corresponding reduction of the component
b) (so that the same NCO/OH equivalent ratio was obtained).
.sup.b) Particularly poor flow and low film thicknesses.
Example A 12
A latex paint containing 1.4 g of the polyurethane thickener from Example 1
and the following ingredients was prepared:
______________________________________
Water 30.5 g
Borchigen ND.sup.1), 25% in water
8.6 g
Borchigen DFN.sup.1), 100%
1.4 g
Nopco 8034 E.sup.2) 2.0 g
Mergal KM 101.sup.3) 2.0 g
Propylene glycol 33.3 g
Butyl diglycol 33.3 g
Methoxybutanol 33.3 g
TiO.sub.2 -RHD 2.sup.4)
220.0 g
Mowilith DM 777.sup.5)
585.0 g
NH.sup.4 OH 4.0 g
S udranol 230.sup.6) 30.0 g
______________________________________
.sup.1) Wetting agent, Gebr. Borchers AG, Goslar
.sup.2) Henkel, D usseldorf
.sup.3) Riedel de Haen
.sup.4) Tioxide
.sup.5) Hoechst AG, Frankfurt/M
.sup.6) S uddeutsche Emulsionschemie, Mannheim
The latex paint had excellent working properties. The following values were
obtained for the viscosity:
______________________________________
Viscosity at [s.sup.-1 ]
[Pa .multidot. s]
1 10 40 80
______________________________________
36 16 10 7
______________________________________
Example A 13
A latex paint containing 6.3 g of the polyurethane thickener from Example 1
and the following ingredients was prepared:
______________________________________
Water 42.0 g
AMP 90.sup.1) 2.6 g
Borchigen DFN.sup.2), 25% in water
15.1 g
Nopco 8034 E.sup.3) 1.0 g
Borchigen DFN.sup.2), 100%
1.0 g
Mergal KM 101.sup.4) 2.1 g
TiO.sub.2 -RHD 2.sup.5)
233.0 g
Propylene glycol 20.0 g
Butyl diglycol 10.0 g
Water 100.7 g
Ubatol 150.sup.6) 560.0 g
______________________________________
.sup.1) Wetting agent, Angus Chemie GmbH, Essen
.sup.2) Wetting agent, Gebr. Borchers AG, Goslar
.sup.3) Henkel, Dusseldorf
.sup.4) Riedel de Haen
.sup.5) Tioxide
.sup.6) Cray Valley Prod. Ltd., Famborough, GB
The latex paint had excellent working properties. The following values were
obtained for the viscosity:
______________________________________
Viscosity at [s.sup.-1 ]
[Pa .multidot. s]
1 10 40 80
______________________________________
14 9 6 4.5
______________________________________
Examples A 14 and A 15
These examples demonstrate that the thickeners according to the invention
have a well-balanced action in an acrylate dispersion. Measurement of
thickening action:
To 98 g each of a commercial polyacrylate dispersion (Dilexo RA3 available
from Condea, 2000 Hamburg) were added 2 g of an aqueous solution of a
thickening composition containing a polyurethane thickener and Borchigen
DFN (firm Borchers, Goslar) in the ratio by weight 1:1. The concentration
of the solutions is 2.5% by weight, based on the polyurethane thickener.
The mixtures thus prepared were stirred for 5 minutes at 2000 rev./min.
The homogeneous dispersions thus obtained were stored for 24 h at
23.degree. C.
The viscosity of the dispersions thus obtained were measured in a Haake
viscometer RV 100, measuring body SV DIN, at 23.degree. C. and 10.3
s.sup.1 :
______________________________________
Example Thickener from
Viscosity
No. Example No. [Pa .multidot. s]
______________________________________
A 14 2 9.9
A 15 5 7.8
______________________________________
Examples 16 to 19
The procedure described in Examples A 14 and A 15 was followed, but varying
quantities of thickener were used. The results are summarized in Table 3.
TABLE 3
______________________________________
Viscosity
of [Pa .multidot. s]
Addition
Example Thickener from at [s.sup.-1 ]
[g]
No. Example No. 10 solution
______________________________________
A 16 2 5.5 1
A 17 2 12.5 4
A 18 5 3.2 1
A 19 5 13.9 4
______________________________________
Examples A 20 to A 23
These examples demonstrate the effectiveness of the thickener according to
the invention for thickening water (Table 4).
TABLE 4
______________________________________
Viscosity
[Pa .multidot. s]
Addition
Example Thickener from at [s.sup.-1 ]
[g]
No. Example No. of 10 solution
______________________________________
A 20 5 2.0 2.5
A 21 6 0.6 2.5
A 22 5 25.0 5.0
A 23 6 27.1 5.0
______________________________________
Although the invention has been described in detail in the foregoing for
the purpose of illustration, it is to be understood that such detail is
solely for that purpose and that variations can be made therein by those
skilled in the art without departing from the spirit and scope of the
invention except as it may be limited by the claims.
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